Ethiopia has blocked social media sites until the national school examinations, which started on Monday, end on Wednesday.

Viber, Facebook, Instagram, YouTube and Twitter have been inaccessible in the country since early Saturday.

On Sunday, the government communications office confirmed blocking the sites temporarily saying it was "for the students to focus on their exam" and "not to be distracted".

The exams were prepared with high caution and have already been dispatched to police stations

End of the year national examinations were originally scheduled for May, but an online leak of one of the examination papers forced government to reschedule them.

Ethiopia's Ministry of Education on Saturday denied rumours that there had been another leak.

"The exams were prepared with high caution and have already been dispatched to police stations located in all exam centres with the necessary safety measures taken," Minister of Education, Shiferaw Shigute, told reporters in Addis Ababa.

Opposition media claimed responsibility for the leaks of the first national school leaving exams after an English exam paper was seen circulating online.